/* ----------------------------------------------------------------------------

 * GTSAM Copyright 2010, Georgia Tech Research Corporation,
 * Atlanta, Georgia 30332-0415
 * All Rights Reserved
 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)

 * See LICENSE for the license information

 * -------------------------------------------------------------------------- */

/**
 * @file    GaussianDensity.cpp
 * @brief   A Gaussian Density
 * @author  Frank Dellaert
 * @date    Jan 21, 2012
 */

#include <gtsam/linear/GaussianDensity.h>
#include <string>

using std::cout;
using std::endl;
using std::string;

namespace gtsam {

/* ************************************************************************* */
GaussianDensity GaussianDensity::FromMeanAndStddev(Key key, const Vector& mean,
                                                   double sigma) {
  return GaussianDensity(key, mean, Matrix::Identity(mean.size(), mean.size()),
                         noiseModel::Isotropic::Sigma(mean.size(), sigma));
}

/* ************************************************************************* */
void GaussianDensity::print(const string& s,
                            const KeyFormatter& formatter) const {
  cout << s << ": density on ";
  for (const_iterator it = beginFrontals(); it != endFrontals(); ++it) {
    cout << "[" << formatter(*it) << "] ";
  }
  cout << endl;
  gtsam::print(mean(), "mean: ");
  gtsam::print(covariance(), "covariance: ");
  if (model_) model_->print("Noise model: ");
}

/* ************************************************************************* */
Vector GaussianDensity::mean() const {
  VectorValues soln = this->solve(VectorValues());
  return soln[firstFrontalKey()];
}

/* ************************************************************************* */
Matrix GaussianDensity::covariance() const { return information().inverse(); }

}  // namespace gtsam
